The present disclosure relates to vehicles, for example, rotorcraft with fluid cooled engines. More specifically, the present disclosure relates to redundant cooling systems for vehicles with fluid cooled engines or fluid cooled systems.
Fluid cooled systems, for example, internal combustion engines, require a cooling system that forces air across a heat exchanger to reject thermal energy from a working fluid that circulates through the engine. The cooling system must function during normal engine operation to prevent the engine from overheating that leads to engine failure. Such a cooling system is prone to failure of any one of the multiple components of the system, such as a fan, duct, heat exchanger or fluid distribution system including pumps and piping network Failure or malfunction of any of these components could lead to cooling system failure and, consequently, engine failure.
In some applications, aircraft have multiple engines for redundancy to meet safety and reliability requirements if a failure of one of the engines occurs. It is difficult to meet safety and reliability requirements if a failure of one of the above components of the cooling system can result in cooling system failure. To overcome this difficulty, the individual components, such as the fan, duct and heat exchanger are robustly designed to increase damage and flaw tolerance, with the penalty of additional weight, increased cost, larger component size, and loss of mission capability of the aircraft.